Model airplane



Jan. 27, 1959 H. A. BEl QGSTRAND MODEL AIRPLANE 2 Sheets- Sheet 1 FiledMarch 18, 1957 v INVENTOR H. A.. BERGSTRAND ATTORNEY Jan. 27, 1959 H. A.BERGSTRAND 2,8

7 MODEL AIRPLANE! Filed March 18, 1957 2 Sheets-Sheet 2 FIG. I3

v INVENTOR. H. A. BERGSTRAND I ATTORNEY United States Patent MODELAIRPLANE Harold A. Bergstrand, East Moline, 11L, assignor toStrombeck-Becker Manufacturing Co., Moline, 11]., a corporation ofIllinois Application March 18, 1957, Serial No. 646,812

' 12 Claims. (Cl. 46-76) This invention relates to a toy or modelairplane and more particularly to improvements in wing and elevatorstructure.

The invention features novelty and simplicity in construction throughthe use of composite and bracing structure enabling the exploitation ofsheet material as the basic material of which the ship is constructed,to the end that the ship may be furnished in kit form for assembly intoa model that is attractive as a display item as well as having goodflight characteristics and resistance to damage in crashes. In apreferred embodiment, the ship is constructed primarily of sheetmaterial such as polystyrene, which itself has certain structuraladvantages in addition to its ability to lend itself to mass productionmethods as well as being economical, light in weight, attractive andeasy to cement, but which also has certain structural disadvantageswhere the sheet portions are of substantial area. Therefore, it is afeature of the invention to utilize tubular or hollow'structure toenhance the strength of the material.

and an improved wing assembly having in addition to such mounting adouble-thickness portion at least adjacent to the fuselage andstrut-receiving pockets in the wing assemblies and fuselage; and suchother features and objects, inherent in and encompassed by theinvention, as will appear from the ensuing detailed description Figure 6is an enlarged section on the line 6--6 of Figure 1.

Figure 7 is an exploded view based on Figure 6.

Figure 8 is a perspective of the underside of the base wing.

Figure 9 is an enlarged section on the line 9-9 of Figure 2.

Figure 10 is a view on the line 1010 of Figure 9.

Figure 11 is an enlarged exploded perspective of the landing gearsupport.

Figure 12 is an enlarged section on the line 12--12 of Figure 9.

Figure 13 is an enlarged section on the line 13-13 of Figure 9.

The ship as it appears in Figure 1 has much the general appearance of aconventional airplane, actually being a scale model to a major extent ofa well-known full-sized model whose identity is of no moment here. Assuch, it has a fuselage 20, right and left wing assemblies 22,

and tail assembly 24 including right and left elevators 26 and a rudderor fin 28. The fuselage is tubular, here shown as made up of right andleft complementary halves It is a primary object to provide a novel wingand/ or elevator mounting.

2,870,568 Patented Jan. 27, 1959 appropriately flanged to be cemented orotherwise secured together along a joint 30 that lies in tne uprightforeand-aft median plane of the ship. The tubular character of thefuselage results from its formation of formed sheet material, onesuitable type of which is polystyrene, which may be commerciallyvacuum-formed. The designation here of this material and/or its formingprocess. does not of course exclude others, but that referred to hasbeen selected because of its accepted use in production of planes of thenature described.

The fuselage thus has an under or belly portion 32 which provides a pairof opposite generally upright foreand-aft side walls 34. Since these aresymmetrical at both sides of the median plane along the joint 30 and arefurther symmetrical relative to components to be described, the shipwill be further dealt with as from one side only, thus avoidingrepetition.

In the formation of the fuselage halves, each side Wall is provided witha fore-and-aft elongated exterior mounting pad 36 of airfoil shape asseen in elevation, and this pad thus has an outer mounting surface 38defined by an upper convex edge 40 and a lower straight edge 42. Thissurface along the lower edge 42 is spaced laterally outwardly fro-m thefuselage side wall 34 to provide a fore-and-aft downwardly facing andinwardly and downwardly sloping ledge or lip 43 (Figures 2 and 7). Theelevators 26 are mounted via similar pads, one of which appears at 44and which, having the configuration and other characteristics justoutlined need not be further described. Each elevator pad 44 mounts itsWing-like elevator element 26, which is of sheet-like construction,having here a single-thickness concavo-convex top wall 46extendingoutwardly from a generally upright foreand-aft wall 48 which has anairfoil shape conforming to that 'of the pad 44. Thus when the elevatoris to be assembled to its pad, the inner surface of the elevator wall 48is coated with suitable adhesive, such as any well known cement, and isplaced congruently with the pad and thus secured thereto. Theconcave-convex section of the elevator top wall conforms generally tothe upper edge of the airfoil shape of the pad. The pad 44, like thewing-mounting pad 36, has its lower edge spaced outwardly from theproximate side of the fuselage to afford a fore-and-aft inwardly slopingand downwardly facing ledge 50 exactly like that at 43, and the elevatormounting wall has along its lower edge a cooperative flange 52 whichprojects inwardly below and is cemented to the ledge, thus materiallyadding to the cementing area and consequently improving the strength ofthe joint. Moreover, since the mounting wall is generally upright to thetop wall 46, it maintains the concavoconvex shape of that top wall andaffords an airfoil? section to the elevator. In a commercial embodimentof the ship disclosed, the various components are vacuumformed in asingle sheet and are cut out therefrom for assembly. The flange 52results simply from leaving the necessary amount of sheet on the endwall 48.

Each wing assembly 22 is of particularly novel design and constructionand comprises a Wing stub 54 and a base wing 56, the latter beingmaterially longer than the former and including an inward portion 58 andan outward portion 60, integrally formedfrom the polystyrene sheet, forexample. The stub 54 overlies the inward portion 58 of the base wing andthe two are generally congruent in this area, although in contact onlyabout their marginal edge portions, as will presently appear, because ofdifferences in cross-section. The stub has an inner fore-and-aft, hereupright, inner end mounting wall 62 of airfoil shape so as to besubstantially congruent with the mounting pad 38 when assembled, andthis wall thus has a convex upper edge 64 and a straight lower edge 66and aer sea a top wall sheet which is here of single thickness and ofconcave-convex section conforming to the convex upper edge As in thecase of the elevator 26, the mounting wall 62 maintains the airfoilshape of the stub, which, in addition to the inner end at 62, has a freeouter end 70 and leading and trailing lateral edges 72 and 74respectively.

When the stub and base wing are assembled, the stub lies on top of andis generally congruent with the inward portion 53 of the base wing, thelatter having an inner fore-and-aft end 76 and front and rear or leadingand trailing edges 78 and 80 respectively. The inner end 76 lies alongthe inner end wall lower edge 66 of the inner stub wall 62 and in thatarea the base wing is of generally section. Since the stub top wallsheet 68 in this area is concavo-convex, the two will be verticallyspaced apart. However, the base wing gradually changes section and at anintermediate portion 82 assumes a concave-convex section conforminggenerally to that of the stub at its outer end 70, whence the base wingcontinues into its outward portion and retains its concavo-convexsection in that outward portion to achieve an airfoil section, themaintenance of which results from the construction and assembly of thestub and base wing as will be described immediately below. tatedotherwise, the wing 22 is of tubular section at its inner part (Figure3), is of double thickness in the zone 82 (Figure 4) and is of singlethickness in its outward part (Figure 5).

The stub mounting wall 62, like the wall 48 of the ele vator 26, hasalong its lower edge a marginal flange 84 which projects laterallyinwardly under and is secured to the lip or ledge 53 of the wing pad 36,this flange being achieved in the manner and serving the purpose andfunction already covered with respect to the elevator mounting. In thepreferred assembly shown, the inner end 76 of the base wing isdownwardly offset to afford an integral fl nge 77 which underlies and issecured to the under side of the stub flange 84, thus assuring the flatsection of the base wing in the area noted. In addition. the stub 54 andbase wing inward portion 58 are secured together at their respectiveleading and trailing ed es 72-78 and 74-450 and the two are furthercemented or otherwise secured together in t e base wing intermediatezone 82 to afford the double-thickness part as shown in Fi ure 4. Hence.when viewed in Figure 6, the stub 54 and base win inward portion 53converge out ardly and meet in the zone 82, and the outward portion 60extends of course beyond that zone. Adiacent to this zone, the base wingis formed with a vertical offset to afford a fore-and-aft shoulder 86 ofa depth commensurate with the thickness of the stub top wall sheet 68and this shoulder receives the outer end of the stub top wall so thatthe upper surfaces of the stub and base wing outward portion aregenerally flush.

The inward portion 5% of the base wing is formed or recessed to provide,just inwardly of'the zone 82. a downwardly facing strut-receiving pocket88 which. because of the nature of the sheet material is also reflectedat the upper surface of the base wing; but. since this pocket is coveredby the proximate sheet portion 68 of the stub 54, it is concealed fromabove. Hence, although the formation of the pocket 8'3 is in trumentalin improving the construction. particularly adding strength to thestructure adiacent to the zone it is concealed as stated above andtherefore does not detract from the authenticity of the model. A tubularstrut 90 has its outer or upper end received in and cemented to thepocket 88 and has its inner or lower end received in and cemented to thefuselage via a fuselage pocket 9?. integrally formed in the fuselagewall 34. The strut is preferably made up of a pair of complementaryhalves cemented together and having web portions 94 and 96 respectivelyoverlapping the edges of the pocket structures and 92., with theadjacent rounded portions of the strut actually entering the pockets.The

pockets are an aid in assembling the components as well as contributingto the maintenance of the respective joints.

A further feature of novelty is the landing gear mounting, which heretakes the form of a pair of wire elements 98. Since these aresymmetrical, only one and its mounting will be described. The wire has astrut or leg 100 which is arranged herein downwardly and outwardlyinclined relation to the median plane of the ship and this legterminates at its lower or outer end as an integral transverse axle 102for journaling a landing wheel 104. The leg 100 has at its upper orinner end a portion 106 in the form of an L made up of a transverse part108 and a fore-and-aft part 110. In keeping with the concealment ofcomponents and joints likely to detract from the authenticity of themodel, the fuselage wall 34 is apertured at 112 to receive the wire 98,so that the leg 100 is external to and the L 106 is interiorly of thewall. The wall has a slight transverse curvature and the L part 108conforms thereto. The fore-and-aft part of the L lies along the fuselageand the L portion is secured to the interior surface of this fuselage bymeans in the form of an L-shaped member 114 having an L-shaped groove116 therein to receive the L-shaped part of the wire. Again cement isused as the adhesive, since the material of the member 114 and that ofthe fuselage may be the same. The transverse part 108 of the L restrainsthe leg against lateral displacement and the fore-and-aft part 110performs the same function relative to fore-and-aft displacement. Inorder to avoid the necessity of producing rights and lofts, the wiresfor the two sides of the ship may be identical and when assembled, thefore-and-aft part of one extends forwardly and the other rearwardly, andthe members 114 are identical but are rotated as respects each otherwhen assembled. In addition to securing and confining the wire-Ls 106,the two members operate as a cross brace in the belly section of thefuselage. v The leg of the wire 98 is concealed by a tubular struthousing 118, preferably made up of a pair of complementary halvescemented together and forming a housing that embraces the wire. Anintermediate portion of the leg is of zig-zag configuration as at 101(Figure 11) and its fore-and-aft disposition within the housing (Figures9 and 13) prevents the housing from turning about the axis of the wireleg 100. Thus, the actual support of the landing gear is via the wires,and the strut housings, although carried by the wires, do not interferewith the flexibility thereof.

Another instance of the exploitation of wire as a stifiener is shown at29 in the fin or rudder 28 (Figures 1 and 2).

The objects and general nature of the improvements wrought here havebeen elaborated along with the description. Features and objects not soenumerated will readily occur to those versed in the art, as will manymodifications and alterations in the preferred inventive embodimentdisclosed, all of which may be achieved without departure from thespirit and scope of the invention.

What is claimed is:

1. A toy airplane, comprising: a fuseleage having a fore-and-aftgenerally upright side wall; a fore-and-aft mounting pad on andexteriorly of said wall and having an outer mounting face of airfoilshape defined by a convex upper edge and a substantially straight loweredge, said face along said lower edge being spaced outwardly from saidside wall to afford a fore-and-aft downwardly facing ledge; a stub wingof sheet construction having inner and outer fore-and-aft ends, leadingand trailing edges and being of concavo-convex section from front torear so as to conform substantially to the convex upper edge of the padface, said stub at its said inner end having a generally upright walldepending from said concavoconvex section and shaped to liesubstantially congruently against and secured to said pad face, saidstub wall having a lower fore-and-aft flange integral therewith andprojecting under and secured to the, pad ledge; and-a base wing of sheetconstruction having an inward portion below and generally congruent withthe stub and an outward portion projecting laterally outwardly beyondthe outer end of said stub, said base wing in its inward portion havingleading and trailing edges secured respectively to the leading andtrailing edges of the stub, and an inner edge secured to the stubflange, said base wing having an intermediate portion under and securedto the outer end of the stub, and said base wing being of substantiallyfiat section at its said inner edge and changing to a concave-convexsection at said intermediate portion to generally conform to the sectionof the stub at the outer end of the stub, whereby the stub and inwardportion of the base wing are spaced vertically apart adjacent to themounting pad and converge to and meet at the junction of the outer endof the stub and said intermediate portion of the base wing.

2. The invention defined in claim 1, in which: said base wing in itsintermediate portion is vertically offset to afford a fore-and-aftshoulder of a depth commensurate with the thickness of the stub sheetand receiving said stub outer end so that the upper surfaces of the stuband the outward portion of the base wing are substantially flush at thejunction therebetween.

3. The invention defined in claim 1, in which: the base wing includes inits inward portion an upwardly recessed part affording a downwardlyopening pocket laterally outwardly of the fuselage and concealed fromabove by the overlying stub; and a strut has one end received in saidpocket and extends downwardly and inwardly to an inner end proximate andsecured to the fuselage.

4. The invention defined in claim 3, in which: th fuselage side wall hastherein an outwardly and upwardly facing pocket receiving the inner endof the strut.

5. A toy airplane, comprising: a fuselage having a fore-and-aftgenerally upright side wall; a stub wing of sheet construction havinginner and outer fore-and-aft ends, leading and trailing edges and beingof concavoconvex section from front to rear and having at said inner enda generally upright wall depending from said concave-convex section andlying proximate to the fuselage side wall, said stub wall having a lowerfore-and-aft straight edge and an upper convex edge joined to saidconcave-convex section; means securing the stub wall to the fuselageside wall; and a base wing of sheet construction having an inwardportion below and generally congruent with the stub and an outwardportion projecting laterally outwardly beyond the outer end of saidstub, said base wing in its inward portion having leading and trailingedges secured respectively to the leading and trailing edges of thestub, and an inner edge secured to the wall lower edge, said base winghaving an intermediate portion under and secured to the outer end of thestub, and said base wing being of substantially flat section at its saidinner edge and changing to a concaveconvex section at said intermediateportion to generally conform to the section of the stub at the outer endof the stub, whereby the stub and inward portion of the base wing arespaced vertically apart adjacent to the fuselage and converge to andmeet at the junction of the outer end of the stub and said intermediateportion of the base wing.

6. The invention defined in claim 5, in which: said base wing in itsintermediate portion is vertically offset to afford a fore-and-aftshoulder of a depth commensurate with the thickness of the stub sheetand receiving said stub outer end so that the upper surfaces of the stuband the outward portion of the base wing are substantially flush at thejunction therebetween.

7. The invention defined in claim 5, in which: the base wing includes inits inward portion an upwardly recessed said pocket and extendsdownwardly and inwardly to an inner end proximate and secured to thefuselage.

8. A toy airplane, comprising: a fuselage having a fore-and-aft sidewall; a fore-and-aft elongated mounting pad on and exteriorly of saidwall and being of generally airfoil shape, having an outer generallyupright mounting face defined by an upper convex edge and a lowerstraight edge, said face along its lower edge being spaced laterallyoutwardly of said wall to afford a fore-and-aft down- 1 wardly facingledge; and a wing-like element having an inner generally uprightmounting face substantially congruent with and having face-to-facecontact with and secured to the pad face and like said pad face havingan upper convex edge and a lower straight edge, said element havingalong its lower edge a fore-and-aft flange projecting laterally inwardlyunder and secured to the pad ledge.

9. The invention defined in claim 8, in which the element is ofsheet-like construction of concave-convex section conforming generallyto the upper convex edge of the pad, said element mounting facecomprises a depending wall integral with said element and said flange isintegral with the lower edge of said element wall.

10. In a toy airplane having a fuselage, a wing assembly comprising: awing stub having a fore-and-aft inner end mounting wall of airfoil shapeincluding an upper convex edge and a lower straight edge, said stubincluding a top wall sheet of concave-convex section joined to andextending laterally outwardly from said convex upper edge of said innerend wall to a fore-and-aft outer end and said top wall having leadingand trailing edges; and a base wing sheet having an inward portionsubstantially congruent with and underlying the stuband an outwardportion extending laterally outwardly be- -yond the outer end of thestub, said inward portion having leading and trailing edges securedrespectively to the leading and trailing edges of the stub and an innerfore-and-aft edge lying along the lower edge of the inner end wall ofthe stub, said base wing sheet further having an intermediate portionunderlying and secured to the outer end of the stub, and said base wingat its inner end being of generally flat section so as to conformgenerally to said inner wall lower edge and thus to be spaced below theproximate portion of the stub top wall sheet and said inward portionchanging to concave-convex section at said intermediate portion toconform to the section of the outer end of the stub, whereby said inwardportion and said stub converge laterally outwardly from said inner walland meet at the junction of said stub outer end and said intermediateportion.

11. The invention defined in claim 10, in which: said base wing in itsintermediate portion is vertically offset to afford a fore-and-aftshoulder of a depth commensurate with the thickness of the stub sheetand receiving said stub outer end so that the upper surfaces of the stuband the outward portion of the base Wing are substantially flush at thejunction therebetween.

12. The invention defined in claim 10, in which: the base wing includesin its inward portion an upwardly recessed part afiording a downwardlyopening strutreceiving pocket concealed from above by the overlying topwall.

References Cited in the file of this patent UNITED STATES PATENTS2,347,689 Johnson May 2, 1944 2,560,742 Reder July 17, 1951 2,676,431Goldberg Apr. 27, 1954 2,724,211 Bloom Nov. 22, 1955 FOREIGN PATENTS630,222 Great Britain Oct. 7, 1949 752,992. Great Britain July 18, 1956

